Intermediate bulk containers (IBC) are ubiquitous in industry. An IBC is a standardized container used for transport and storage of fluids and bulk materials. The construction of an IBC varies depending on the application. For example, there are foldable (collapsible) IBCs, plastic composite IBCs, steel IBCs, and stainless steel IBCs. IBCs offer a number of advantages. For example, they are generally cubic in form and therefore can transport more material in the same area than cylindrically-shaped containers, such as drums, or consumer-sized packages. Additionally, a manufacturer of a product can bulk package the product in an IBC in one location, ship it at a reasonably low cost to another location, and then repackage the product in its final consumer form in accordance with local regulations in a form and language suitable for that location. Furthermore, because IBCs are standardized, over the years, systems have been developed, world-wide, for filling and discharging them.
Typically, an IBC has two valves. One valve is a fuseable type valve, which is used to avoid catastrophic internal pressure. Specifically, fuseable valves are designed to irreversibly pop open when the pressure inside the container exceeds a certain point to prevent the container's explosion. Such fuseable valves are designed primarily for situations involving excessive heat, for example, fire. Typically, the pressure differential needed to pop these valves is between 2 and 10 psig. It is important to note that fuseable valves are irreversible, meaning that, once they pop, they cannot be reused and need to be replaced.
The other valve is a pressure/vacuum relief valve for pressure differentials that occur between the container pressure and ambient under ordinary conditions—e.g., ordinary temperature fluctuation throughout the day. One common pressure valve is the GITS valve commercially available through GITS Manufacturing, Creston, Iowa. This valve has become essentially a defacto standard in the industry and serves to both pressure vent and vacuum vent.
Despite the ubiquitous use of the GITS valve in IBC applications, Applicants have identified a number of problems associated with the GITS valve. For example, it tends to leak in its closed state, causing unintentional discharge of the contained material. This can be particularly problematic if the contained material is caustic or otherwise environmentally hazardous. Additionally, GITS valves tend to be unreliable, and the pressure differential at which the valve is supposed to vent tends to vary over the life of the valve and among different valves. In general, the valve's venting performance is not reliable. Furthermore, the GITS valve is susceptible to damage and is not regarded as being sufficiently rugged for industrial environments.
Therefore, a valve having improved reliably and ruggedness is needed. The present invention fulfills this need among others.